Dampened railway bogie bolster



United States Patent Inventor Frederick William Sinclair Qlwsss Engl n721 ,371 Filed April 15, 1968 Patented Oct. 27, 1970 Assignee GloucesterRailway Carriage & Wagon Company Limited Gloucester, England PriorityApril 15, 1967 Great Britain 17,3 87/67 DAMPENED RAILWAY BOGIE BOLSTER12 Claims, 10 Drawing Fig.

US. Cl 105/197, 105/202, 105/206 Int. Cl. B6lf3/08, B6 lf 5/ l 2 Fieldof Search 105/ 1 97D,

[56] References Cited UNITED STATES PATENTS 1,894,386 1/1933 Webb..l05/l97(D)UX 2,190,643 2/1940 Hobson... ..105/197(D)UX 3,245,3574/1966 Sinclair ..l05/l97(D)UX Primary ExaminerArthur L. La PointAssistant Examiner-Howard Beltran Attorney-Young & Thompson ABSTRACT: Arailway bogie including two side frames each of which has two spacedhollow guide columns defining between them a bolster guide within whichthe corresponding end of a bolster slides vertically during normalsuspension movement. One column of each side frame houses damping meansoperative, through the intermediary of a member connected to thebolster, to apply a greater damping force to the bolster when the bogieis in a loaded condition as compared with the damping force applied tothe bolster when the bogie is in an unloaded or tare condition.

Patented Oct. 27, 1970 Shae t INVENTOR Razz/c4 Wu 4 mam/aw Patented Oct.2 7, 1970 Sheet w R w 3 1 Q e m ww p 4 m? k Q ,N, llll W m wv .fi J. g\Wmm m A WWW. mm, R MM m R 25 F R Q Q m v uww r /A BY ATTORNEYS PatentedOct 27, 1970 Sheet INVENTOR feepse/c/zwu/nmJ/mcznw ATTORNEYS Mama 0a.27, 1910 3,536,012

Sheet 5 016 W7 r Jw w ATTORNEYS DAMPENED RAILWAY BOGIE BOISIER Thisinvention relates to railway bogies of the type in which a lateralbolster for supporting a vehicle superstructure is vertically movable inbolster guides in two side frames. The bolster is supported by the bogiesuspension and damping means are provided to prevent undue verticaloscillation of the bolster.

According to the invention a railway bogie includes two side frames eachof which has two spaced guide columns defining between them a bolsterguide within which the corresponding end of a bolster slides verticallyduring normal suspension movement, with at least one column of each sideframe supporting, and preferably housing, damping means operative,through the intermediary of a member which follows vertical movement ofthe bolster within the corresponding guide, to apply a greater dampingforce to the bolster when the bogie is in a loaded condition as comparedwith the damping force applied to the bolster when the bogie is in anunloaded or tare condition. This provides load sensitive damping as thearrangement is such that a light damping force is applied when thevehicle is running light and the damping force is materially increasedwhen the vehicle is loaded with consequent downward movement of thebolster to a new suspension equilibrium position.

In assembling bogies of the foregoing type, each end of the bolster mustbe inserted between the two corresponding guide columns but below theguide and then raised into the guide, after which suspension springs arefitted between the underside of the bolster and a lower web orcrossmember of the side frame which interconnects the guide columnsbelow the guide. If load sensitive damping is required, damper springsare commonly mounted between the bolster and the web of the side frame,but lack of space due to the presence of the bolster complicates thefitting of the damper springs and also means that the latter must becompact. However. in the present invention, the damping means need notbe particularly compact and can be fitted in the appropriate guidecolumn before the bolster is fitted in the side frame.

Preferably friction damping means are employed with a damper shoe whichprojects from the corresponding guide column into the bolster guide forfrictional engagement under the action of a damper spring which ishoused within the guide column and the compression of which is varied bymovement of said member to vary the damping force. Practicable alternative arrangements may employ any form of telescopic damper of eitherthe hydraulic or rubber energy absorption type in which case thetelescopic damper is connected to the bolster through said member whichapplies the damping force to the bolster. Yet another alternative mayemploy rubber energy absorbing damping means of the type in which aplunger having a corrugated profile is forced into a conical bore ofdecreasing diameter. As used with the invention, the plunger isconnected to said member through which the damping force is applied tothe bolster.

Whether friction or telescopic damping means are employed, said membermay be in the form of a bellcrank lever one limb of which engagesbeneath the bolster so as to be displaced thereby as a result ofvertical bolster movement and the other limb of which is connected tothe damping means; with a telescopic damper it is necessary to attachthe bellcrank lever both to the damper and underneath the bolster as thelever has to be double-acting, whereas with the spring friction damperarrangement no lever attachments are necessary and the lever can merelyengage a suitable abutment-beneath the bolster. In either case thebellcrank lever translates vertical bolster movement into a horizontalmovement operative at the damping means so that a progressive andcontinuously variable damping action is obtained. However, in the caseof friction damping by a helical compression spring the bellcrank levermaybe dispensed with and the change of damping force with verticalbolster movement may follow any desired characteristic by means of a camand cam follower arrangement which preferably transmits movement of themember into appropriate movement of an actuating lever which ispivotally movable to vary the damping force. v

Said member may take the form of a yoke the two side limbs of which arepivotally mounted on the guide column on a transverse pivot axis, Le. anaxis extending parallel to the bolster between the side frames.Preferably, the free ends of the limbs are respectively located inpockets in the bolster and the inner surface of the intermediatelimbcooperates-with a cam formation on the actuating lever one end ofwhich is pivotally mounted about a transverse pivot axis 'below thedamping means and the other end of which effects horizontal movement ofan outer spring abutmentof the spring. If desired, the arrangement maybe such that the dampiiigriieans applies a constant damping force over alight load range and a constant but increased damping force over a moreheavily loaded load range. To achieve this, said member may carry a camwhich cooperates with a cam follower carried by the actuating lever. Inorder to provide the aforesaid damping characteristics, the cam willnormally have upper and' lower vertical surfaces which the followerrespectively engages when the bogie is in the lightly loaded and heavilyloaded conditions and which are interconnected by an inclined transitionsurface along which the cam follower rides when the load on the bogiechanges between the lightly loaded and heavily loaded conditions.

It will be appreciated that a bolster of a bogie incorporating the camand follower arrangement previously described in the immediatelypreceding paragraph may undergo small vibrational movement in either anunloaded (or very lightly loaded) or a heavily loaded condition withoutthe prevailing damping force on the bolster changing. In certaincircumstances it is desirable to provide an increasing damping forceduring the upward movement of each bolster vibration within the guidesand a decreasing damping force during the downward movement of eachbolster vibration and this is preferably achieved by suitableinclination of the upper and lower surfaces of the cam so that the smallvibrational movement of the bolster is accompanied by pivotaloscillations of the lever. In one'arrangement, the cam profile is formedon the actuating lever and the profile is engaged by a block carried bysaid member.

The invention will now be further described with reference to theaccompanying drawings which show, by way of example, four forms ofrailway vehicle bogie in accordance with the invention. In the drawings:

FIG. '1 is a perspective view of the first bogie with parts cut away andone side frame detached for clarity.

FIG. 2 is a fragmentary sectional view. to a larger scale. of one sideframe of the bogie of FIG. 1, taken on a fore-and-aft vertical plane,

FIG. 3 is a fragmentary sectional view on the line III-III of FIG. 2,

FIG. 4 is a fragmentary end view on the line IV-IV of FIG FIG. 5 is aview generally similar to FIG. 3, but showing the second form of bogie,

FIG. 6 is a fragmentary and diagrammatic side view of the bogie of FIG.5,

FIG. 7 is a diagrammatic fragmentary plan view showing the third form ofbogie,

FIG. 8 is an explanatory fragmentary side view of the bogie shown inFIG. 7,

FIG. 9 is a fragmentary side view of the fourth form of bogie, and

FIG. 10 is a fragmentary plan view of the bogie shown in FIG. 9.

Referring to FIG. 1, the bogie has a pair of side frames 1 provided withaxle boxes 2 for the usual wheel axle sets 3, and a transverse bolster 4extends centrally between the side frames 1 each of which has a guidedefined by two hollow guide columns 5 between which the correspondingone of two ends 6 of the bolster 4 slides vertically. Suspension springs7 are mounted between each end 6 of the bolster 4 and a central web 8 ofthe corresponding side frame 1, and the bolster 4 has the usual loadbearing centre pivot 9 and side bearers 10 for the vehicle body (notshown) which is mounted on two spaced bogies in the usual manner.

Each guide column 5 of each side frame 1 supports a damper housing 12from which a damper shoe 13 with a friction facing 14 projects into theguide for frictional engagement with the adjacent side face 15 of thecorresponding end 6 of the bolster 4. As shown in FIG. 3, the frictionalfacings 14 on the damper shoes 13 are convex in plan view and-each shoe13 is located for self-aligning movement between upper and lower collets16 and 17 respectively which are horizontally slidable between upper andlower guides 18 and 19 respectively. The guides 18 and 19 areconstituted by U-shaped webs which are integrally cast with theremainder of the side frame, and in particular with side and end walls20 and 21 respectively of the corresponding guide column 5. Each upperguide adjoins a tubular cross member 22 which is shown in F 1G. I andthe lower wall 22a of which is shown in FIG. 2.

Each damper shoe 13 has upper and lower convex arcuate faces 23 and 24respectively against which are urged, by an associated damper spring 25,planar surfaces 26 and 27 formed on the corresponding upper and lowercollets: 16 and 17 respectively. The collets 16 and 17 are recessed sothat they cooperate to form a circular aperture 28 through which thespring passes and an internal space 29 which, in the side view of FIG.2, appears generally semicircular. The spring 25 is disposed between aninner abutment plate 30, which engages shoulders 31 and 32 on thecollets l6 and 17 respectively, and an outer abutment plate 33. Thespring is located transversely by tubular guide stems 34 and 35 weldedto the abutment plates and 33 respectively.

Each spring 25 thus acts on the corresponding pair of collets 16 and 17and urges them towards the bolster 4 to provide the damper force. andthis arrangement not only allows self-aligning movement of theassociated shoe 13, which in effect tends to be squeezed out frombetween the collets l6 and 17, but also urges the collets l6 and 17themselves apart so that wear in the housing 12 is automatically takenup.

A bellcrank lever 36 is mounted on the shank of a bolt 37 supportedbetween the side walls 20 of each guide column 5 and pivots about anaxis A-A. The lever 36 has a generally horizontal lower arm 38 with anupturned end 39 which projects into the guide for engagement withanabutment pad 40 welded to the under surface 42 of the bolster 4. Theother arm 43 of the lever 36 is upwardly and generally verticallydirected and it engages a yoke 44 welded to the abutment plate 33. Thusas the bolster 4 rises and/or falls due to dynamic fluctuations when thevehicle is running, or due to changing loading of the vehicle, the lever36 is displaced to vary the compression of the damper spring 25 andhence the frictional damping force applied to the bolster 4. It will beappreciated that when the vehicle is unloaded less damping force isexerted as the bolster 4 will stand higher from rail level in relationto the side frame 1 than is the case when loaded, with correspondinglyless compression of the damper spring 25 this condition being shown infull lines in FIG. 2. When the vehicle is loaded the bolster 4 movesdown as the suspension springs are compressed, thus increasing thedamping force as a result of the attendant pivotal movement of the lever25 as shown in broken lines in FIG. 2.

The lever 36 is of fabricated form with two cranked side plates 36a and36b which at the upper ends are joined bya crosspin 45 which is locatedbetween the limbs 46, of the yoke 44 and at the lower ends are joined bya crossmember 47 with a convex upper surface 48 which engages theabutment pad 40 with a generally rolling action during bolster movement.The lower arm 38 of each bellcrank lever 36 passes through apertures 49in the end walls 21 of the corresponding guide column 5, and the outerend wall 21 of each column 5 terminates at its upper end in two alignedbearing bosses 50 responding bellcrank lever 36, and a thrust washer 54is positioned between each boss 50 and the adjacent radial face of thesleeve 53. A retaining nut 55 is screwed on to the end of each bolt 37.It will be appreciated that sirnilar'opposed damping arrangements areprovided at each end of the bolster 4.

In FIGS. 5 to 10 parts corresponding'to those in'FIGS. l to 4 have beengiven the same reference numerals; in each of the three constructionsshown in FIGS. '5 to 10 the-damping means are generally as haspreviously been described in that the means comprise a damper sh'o'e 13engaged by two collets 16 and 17 with a helical compression spring 25prosgding the damping force. The constructions of FIGS. -5 to 10 digitsfrom the arrangement of FIGS. 1 to 4 only in the manner Err-whichvertical bolster movement is translated into horizontal movement at thedamping means, and hence FIGS. 5 to -10show mainly those parts of thesecond to fourth forms of bogie in so far as they differ from the firstform shown in FIGSJI to 4.

Referring to the construction of FIGS. 5 and 6,.two cranked actuatinglevers are pivoted at their respective upper ends about a transverseaxis B (FIG. 6) and are pivotally movable to alter the damping force.The levers 60 are mounted externally of the guide column 5 and arepivotally connected at an intermediate point by a yoke 62, anintermediate portion 63 of which provides an outer end movable abutmentfor the spring 25 of the damping means. The lower ends of the levers 60carry between them a roller forming a cam follower 64 which cooperateswith a cam member 65 supported on two spaced brackets 66 secured to anddepending from the bolster 4.

The cam member 65 is movable in a vertical direction with the bolster 4and has upper and lower vertical cam surfaces 67 and 68 respectivelyinterconnected by an inclined surface 69, the profile of the cam 65 thusbeing generally stepped as shown in FIG. 6. When the bogie is unloadedthe cam member 65 is arranged so that the cam follower 64 engages thelower vertical surface 68, this condition being shown in FIG. 6 fromwhich it can be seen that as the bogie is loaded and accompanyingdownward movement of the bolster 4 occurs, the cam follower 64 ridesalong the inclined surface 69 causing pivotal movement of the levers 60and corresponding compression of the spring 25, with the result that aprogressively increasing damping force is applied to the bolster 4 untilthe cam follower 64 engages the upper vertical surface 67. As thesurfaces 67 and 68 are vertical, the bolster can undergo smallvibrational movement in either of the loaded or unloaded conditionswithout altering the magnitude of the prevailing damping force.

The cam member 65 is mounted on the bracket 66 with a small degree ofhorizontal play so that the lateral thrust exerted by the cam follower64 on the cam member 65 as a result of the action of the spring 25 is'resisted by an adjacent end face 70 of the guide column 5. This ensuresthat no horizontal thrust is applied to the bolster 4, which enablesdamping means to be fitted to one column 5 only of each side framerather than two which would otherwise be necessary for balancing thelateral forces on the bolster 4.

The construction of FIGS. 7 to 8 employs two levers 72 and 73 which aresecured to a common transverse shaft 74 and which together translatevertical movement of the bolster 4 into horizontal movement at an outerabutment 75 of the spring 25. As shown in FIG. 8, the lever 72 has anupper end through which the corresponding bolt 37 passes. The shank ofnose portion 76 which engages the abutment 75 centrally between two sideflanges 77 of the latter. and the lower end of the lever 72 is securedto the shaft 74 which extends between and is pivotally mounted in thetwo side walls 20 of the column 5 below the damping means.

The shaft 74 has a projecting'inner end on which is mounted the lever 73which, as shown in FIG. 8, has an upper end 79 with a cam profile whichcooperates with a convex surface of a block 80 supported by a rod 82carried by the bolster 4. The block 80 engages an upper surface 83 ofthe cam profile when the bogie is in the unloaded condition (as shown inFIG. 8), the block 80 riding along an intermediate surface 84 andfinally a lower surface 85 as the loading, on the bogie in-- creases.

It will be seen from FIG. 8 that the surfaces 83 and 85 are suitablyinclined so that small vibrational movement of the bolster 4 in eitherthe loaded or unloaded conditions causes corresponding fluctuation inthe damping force provided by the spring 25. The surfaces 83 and 85 areinclined in a direction such that, in either the loaded or unloadedconditions, the damping force increases during the upward movement ofeach vibration of the bolster 4 within the guides, and a decreasingdamping force during downward movement of the bolster. Such aconstruction gives smoother running characteristics with less bounce.

The block 80 has a horizontally elongated slot 86 to receive the rod 82,the small amount of horizontal play ensuring that the lateral thrustexerted by the lever 73 on the block 80 is resisted by a projecting sideflange 87.

The fourth form of bogie shown in FIGS. 9 and employs a yoke 90 the sidelimbs 92 of which embrace the guide column and are pivotally mountedthereon about a transverse axis CC by means of bolts 93 screwed into theside walls of the column 5. The two extreme ends 94 of the yoke 90respectively engage pockets 95 formed in the bolster 4 so that verticalmovement of the latter within the guides causes corresponding pivotalmovement of the yoke 90. The intermediate limb 96 of the yoke 90 isformed with a convex edge surface 97 which cooperates with a camformation 98 on an upper outer edge of an actuating lever 99 the lowerend of which is pivotally mounted, about a transverse axis D, betweentwo lugs 100 of the guide column 5.

The upper end of the actuating lever 99 has a projecting nose 102 inengagement with the outer spring abutment 75 of the damping means sothat pivotal movement of the actuating lever 99 causes movement of theouter spring abutment 75 and attendant variation in the compression ofthe spring and the magnitude of the damping force applied to the bolster4. In FIG. 9, the position of the yoke 90 shown in broken linesrepresents the fully loaded condition of the bogie. it will beappreciated that the profile of the cam formation 98 may be chosen togive any required relationship between the variation in bolster positionand the variation in the damping force applied to the bolster 4. As theyoke 90 does not apply any lateral force to the bolster 4, it is notnecessary to fit damping means in each guide column 5 of each sideframe, one damping means in each side frame being sutficient.

Although the surfaces 67 and 68 on the cam 65 of FIG. 5 are vertical, itwill be appreciated that they may, if desired, be inclined to thevertical by a small amount to give, in either the unloaded or fullyloaded conditions, an increasing damping force during the upward bolstermovement of each bolster vibration and a decreasing damping force duringthe downward movement of such vibration.

I claim:

1, A railway bogie comprising two spaced side frames, a laterallyextending bolster supported between the side frames, each side framehaving two spaced columns defining between them a bolster guide withinwhich the corresponding end of the bolster slides vertically duringnormal suspension movement of the bolster and, at each side of thebogie, damping means supported by one of said columns of thecorresponding side frame and operative to apply a damping force to thecorresponding end of the bolster during said suspension movement, and adamping control member mounted on the corresponding side frame formovement as a result of said suspension movement of the bolster, saidmember acting on the corresponding damping means in such manner as toincrease the effective damping force as the bolster moves downwardlyfrom a position corresponding to an unloaded tare condition of the bogieto a position corresponding to a loaded condition of the bogie.

2. A railway bogie according to claim 1, wherein said damping controlmember is a lever which acts on the damping means and is pivotallymounted on the corresponding side frame for pivotal damping controlmovement as the bolster moves alon the correspondin bolster ui de.

3. A rai way bog e accor mg to calm 2, wherein said member is abellcrank lever which is pivoted about a transverse axis and one limb ofwhich engages beneath the bolster so as to be displaced thereby as aresult of vertical bolster movement, the other limb being operative atthe damping means to vary the damping force.

4. A railway bogie according to claim 3, wherein said one limb of thebellcrank lever is generally horizontal and has an upturned end with aconvex upper surface which engages an abutment pad welded to the undersurface of the bolster.

5. A railway bogie according to claim 1, wherein said one column ishollow and houses the damping means alongside the bolster guide.

6. A railway bogie according to claim 5, wherein the damping meansemploy friction damping and comprise a damper shoe which projects fromthe corresponding guide column into the bolster guide for frictionalengagement with the side of the bolster at the corresponding end of thelatter under the action of a damper spring, with movement of said memberin a direction corresponding to downward displacement of the bolsterbeing operative to compress the spring and hence increase the dampingfriction.

7. A railway bogie according to claim 6, wherein said damping controlmember is a cranked lever which adjacent its upper end is pivotallymounted on the corresponding side frame and the lower end of which isdisplaceable by the bolster to produce pivotal damping control movementof the lever, the lever acting on the damper spring at an intermediatepoint along the length of the lever.

8. A railway bogie according to claim 1, wherein movement of said memberis transmitted into movement operative at the damping means through theintermediary of a cam and cam follower arrangement with a cam profileshaped to give the desired characteristic between the variation inbolster position and the variation in the damping force.

9. A railway bogie according to claim 8, wherein the cam profile isformed on an edge surface of an actuating lever which is pivotallymovable to alter the compression of the spring and which is engaged bysaid member which is pivotally mounted with respect to the guide column.

10. A railway bogie according to claim 9, wherein said member takes theform of a yoke the intermediate limb of which engages the cam profile onthe actuating lever and the two side limbs of which embrace and arepivotally mounted on the guide column about a transverse axis, with theextreme ends of the side limbs projecting into pockets in the bolster sothat vertical movement of the latter causes corresponding pivotalmovement of the yoke.

11. A railway bogie according to claim 8, wherein the cam profile isarranged to provide a constant damping force over a light load range anda constant but increased damping force over a more heavily loaded loadrange.

12. A railway bogie according to claim 8, wherein the cam profile isarranged to provide an increasing damping force during the upwardmovement of the bolster during vibration of the latter within the guidesand a decreasing damping force during the downward movement during suchvibration.

